基于聚焦探头的带包覆层管道复杂结构部位脉冲涡流检测研究

脉冲涡流检测技术在带包覆层管道腐蚀缺陷检测中展现出优势而引起广泛关注。本研究设计了一种脉冲涡流聚焦探头，通过有限元仿真与试验，研究其在复杂结构部位中的检测能力。仿真结果显示，设计的脉冲涡流聚焦探头能有效聚集磁场与涡流场能量，有利于对局部缺陷与复杂结构中的缺陷进行检测。通过探究聚焦探头在提离10~50 mm下对管道焊缝及各种尺寸局部缺陷的检测灵敏度，分析其检测能力与提离检测极限，以及在检测过程中的信号特征。结果表明，聚焦探头在提离50 mm下仍能检出尺寸为40 mm×40 mm×1 mm（长×宽×深）的方形局部腐蚀缺陷，焊缝信号的凸起特征、缺陷信号的下凹特征与仿真结果相印证。

Study of Detection on Complex Structural Parts of Insulated Pipes Based on Focusing Probe with Pulsed Eddy Current

Pulsed eddy current testing has shown its advantages in the detection of corrosion of insulated pipes and attracted widespread attention. In this study, a pulsed eddy current focusing probe was designed, and its detection ability in complex structural parts was studied through finite element simulation and experiments. The simulation results show that the designed pulse eddy current probe can effectively gather the energy of magnetic field and eddy current field, which is conducive to the detection of local defects and defects in complex structures. By exploring the detection sensitivity of the focusing probe to the pipeline welds and various sizes of local defects under the lift-off of 10 to 50 mm, the detection ability, lift off detection limit and signal characteristics in the detection process were analyzed. The results show that the focusing probe can still detect the square local corrosion defect of 40 mm× 40 mm× 1 mm (length × wide × deep) in size when lifted 50 mm away, and the convex feature of the weld signal and the concave feature of the defect signal are consistent with the simulation results.